Cisco Cisco Web Security Appliance S670 User Guide

Create an internally resolvable DNS name that starts with “wpad,” such as 
wpad.example.com.

Place wpad.dat in the root directory of the website that will host the file, such as 
wpad.example.com. For information about placing the file on the Web Security 
appliance, see 

Due to a bug in Internet Explorer 6, create a copy of wpad.dat and change 
the file name to wpad.da to work with Internet Explorer 6 users. For more 
information, see 
http://www.microsoft.com/technet/isa/2004/ts_wpad.mspx. 

Configure the web server to set up .dat files with the following MIME type:

application/x-ns-proxy-autoconfig

 

If you place wpad.dat on the Web Security appliance, the appliance does 
this for you already.

You can configure browsers to explicitly use the Web Proxy by using proxy 
auto-config (PAC) files. You can place PAC files on the Web Security appliance, 
and then configure the browsers in one of two ways: enter the URL of a PAC file 
on the appliance, or set the browsers to automatically detect the PAC file by using 
the Web Proxy Autodiscovery Protocol (WPAD).

You can add multiple PAC files to the appliance. You might want to add multiple 
PAC files if the appliance is used by multiple domains on the network. You can 
use one PAC file for all browsers on a domain.

When you add a PAC file to the appliance, you can specify one or more ports the 
appliance uses to listen for PAC file requests. For information on specifying the 
PAC file URL when it is hosted on the Web Security appliance, see 

.

When a browser asks for a PAC file, the appliance sends the file using HTTP. The 
PAC file is returned using MIME type 

application/x-ns-proxy-autoconfig

.